Linkage Error while setting up webApp

Question

          Hi,
          In my webApp I bumped into following Exception while running JSPs which queries
          database.
          Platform : Windows NT 4, webLogic 5.1 with SP 8.
          Action : WLSServer crashes with Dr. Watson application error.
          I am using a custom Connect.java class ( through javax.sql.DataSource, as recommended
          by WLS 5.1 docs ) to connect to Oracle database using JDBC thin client. If I do
          not use webApp architecture then the same class works good to connect to DB.
          Also, if I maintain identical class hierachy into my weblogic.class.path classpath
          settings I do not get this exception and everything works fine.
          I read into this search group messages about Linkage problems caused because of
          having duplicate classes available to the server at runtime and so I ensured that
          I do not keep classpaths which can cause duplicate classes into runtime environment
          of wlsserver but still the same problem persists.
          any help is appreciated,
          thanks,
          - Rajesh.
          Mon Apr 02 16:19:11 PDT 2001:<I> <WebAppServletContext-eTools> Generated java
          file: c:\project\etools\WEB-INF\_tmp_war_eTools\jsp_servlet\_jsp\_xyz.java
          Mon Apr 02 16:19:13 PDT 2001:<E> <WebAppServletContext-eTools> Servlet failed
          with Exception
          java.lang.LinkageError: Class java/sql/Connection violates loader constraints
          at weblogic.jdbc20.common.internal.RmiDataSource.getConnection(RmiDataSource.java:53)
          at weblogic.jdbc20.common.internal.RmiDataSource_ServiceStub.getConnection(RmiDataSource_ServiceStub.java,
          Compiled Code)
          at com.bea.etools.common.Connect.getConnection(Connect.java:51)
          at jsp_servlet._jsp._xyz._jspService(_xyz.java, Compiled Code)
          at weblogic.servlet.jsp.JspBase.service(JspBase.java:27)
          at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:106)
          at weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImpl.java:907)
          at weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImpl.java:851)
          at weblogic.servlet.internal.ServletContextManager.invokeServlet(ServletContextManager.java:252)
          at weblogic.socket.MuxableSocketHTTP.invokeServlet(MuxableSocketHTTP.java:364)
          at weblogic.socket.MuxableSocketHTTP.execute(MuxableSocketHTTP.java:252)
          at weblogic.kernel.ExecuteThread.run(ExecuteThread.java, Compiled Code)
          

Answer 1

Hi again
          Plase check you JAVA_CLASSPATH and WEBLOGIC_CLASSPATH variables
          make sure the paths. May be, the script that you use, define the class in
          the incorrect path
          Rajesh <[email protected]> escribió en el mensaje de noticias
          [email protected]...
          >
          > Hi,
          > The problem is solved.
          > I have 4.5.2 and 5.1 versions of webLogic installed on my machine
          > and in my system classpath I had
          > c:\weblogic452\classes\boot;c:\weblogic510\boot which caused this problem
          > I removed c:\weblogic452\classes\boot from the above classpath and it
          works.
          >
          > I tried to tweak through the above weblogic classes dirs and I did not
          find anything
          > similar to below classes for which the I got Linkage error.
          >
          > question is why would weblogic look for
          weblogic.jdbc20.common.internal.RmiDataSource.getConnection
          > ( (this class resides in c:\weblogic452\classes dir and not in
          c:\weblogic452\classes\boot
          > which is there in system classpath)of /weblogic452 directory when I am not
          even
          > booting up 4.5.2 instance of the server.
          >
          > >java.lang.LinkageError: Class java/sql/Connection violates loader
          constraints
          > > at
          >weblogic.jdbc20.common.internal.RmiDataSource.getConnection(RmiDataSource.j
          ava:53)
          >
          >
          > "Rajesh" <[email protected]> wrote:
          > >
          > >Hi,
          > >
          > >In my webApp I bumped into following Exception while running JSPs which
          > >queries
          > >database.
          > >
          > >Platform : Windows NT 4, webLogic 5.1 with SP 8.
          > >Action : WLSServer crashes with Dr. Watson application error.
          > >
          > >I am using a custom Connect.java class ( through javax.sql.DataSource,
          > >as recommended
          > >by WLS 5.1 docs ) to connect to Oracle database using JDBC thin client.
          > >If I do
          > >not use webApp architecture then the same class works good to connect
          > >to DB.
          > >
          > >Also, if I maintain identical class hierachy into my weblogic.class.path
          > >classpath
          > >settings I do not get this exception and everything works fine.
          > >
          > >I read into this search group messages about Linkage problems caused
          > >because of
          > >having duplicate classes available to the server at runtime and so I
          > >ensured that
          > >I do not keep classpaths which can cause duplicate classes into runtime
          > >environment
          > >of wlsserver but still the same problem persists.
          > >
          > >any help is appreciated,
          > >
          > >thanks,
          > >
          > >- Rajesh.
          > >
          > >------------------
          > >
          > >Mon Apr 02 16:19:11 PDT 2001:<I> <WebAppServletContext-eTools> Generated
          > >java
          > >file:
          c:\project\etools\WEB-INF\_tmp_war_eTools\jsp_servlet\_jsp\_xyz.java
          > >Mon Apr 02 16:19:13 PDT 2001:<E> <WebAppServletContext-eTools> Servlet
          > >failed
          > >with Exception
          > >java.lang.LinkageError: Class java/sql/Connection violates loader
          constraints
          > > at
          weblogic.jdbc20.common.internal.RmiDataSource.getConnection(RmiDataSource.ja
          va:53)
          > > at
          weblogic.jdbc20.common.internal.RmiDataSource_ServiceStub.getConnection(RmiD
          ataSource_ServiceStub.java,
          > >Compiled Code)
          > > at com.bea.etools.common.Connect.getConnection(Connect.java:51)
          > > at jsp_servlet._jsp._xyz._jspService(_xyz.java, Compiled Code)
          > > at weblogic.servlet.jsp.JspBase.service(JspBase.java:27)
          > > at
          weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java
          :106)
          > > at
          weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
          l.java:907)
          > > at
          weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
          l.java:851)
          > > at
          weblogic.servlet.internal.ServletContextManager.invokeServlet(ServletContext
          Manager.java:252)
          > > at
          weblogic.socket.MuxableSocketHTTP.invokeServlet(MuxableSocketHTTP.java:364)
          > > at
          weblogic.socket.MuxableSocketHTTP.execute(MuxableSocketHTTP.java:252)
          > > at weblogic.kernel.ExecuteThread.run(ExecuteThread.java, Compiled
          > >Code)
          >